Larval food composition of four wild bee species in five European cities

Urbanization poses threats and opportunities for the biodiversity of wild bees. A main gap relates to the food preferences of wild bees in urban ecosystems, which usually harbour large numbers of plant species, particularly at the larval stage. This data sets describes the larval food of four wild bee species (i.e. Chelostoma florisomne, Hylaeus communis, Osmica bicornis and Osmia cornuta) and three genera (i.e. Chelostoma sp., Hylaeus sp, and Osmia sp.) common in urban areas in five different European cities (i.e. Antwerp, Paris, Poznan, Tartu and Zurich). This data results from a European-level study aimed at understanding the effects of urbanization on biodiversity across different cities and citiscapes, and a Swiss project aimed at understanding the effects of urban ecosystems in wild bee feeding behaviour. Wild bees were sampled using standardized trap-nests in 80 sites (32 in Zurich and 12 in each of the remaining cities), selected following a double gradient of available habitat at local and landscape scales. Larval pollen was obtained from the bee nests and identified using DNA metabarconding. The data provides the plant composition at the species or genus level of the different bee nests of the studied species in the studied sites of the five European cities. For Hylaeus communis, this is the first study in reporting larval food composition.城市化对野生蜂类的生物多样性兼具威胁与机遇。当前研究的核心缺口聚焦于城市生态系统中野生蜂类的食物偏好：城市生态系统往往承载着丰富的植物类群，这一特征在幼虫阶段尤为突出。本数据集记录了欧洲5座不同城市（安特卫普 (Antwerp)、巴黎 (Paris)、波兹南 (Poznan)、塔尔图 (Tartu) 及苏黎世 (Zurich)）常见的4种野生蜂类（即花长角切叶蜂 (Chelostoma florisomne)、普通黄脸蜂 (Hylaeus communis)、红壁蜂 (Osmia bicornis)、角额壁蜂 (Osmia cornuta)）以及3个类群（即切叶蜂属 (Chelostoma sp.)、黄脸蜂属 (Hylaeus sp.)、壁蜂属 (Osmia sp.)）的幼虫食物来源。本数据集源自两项研究：一项是旨在探究不同城市及城市景观中城市化对生物多样性影响的欧洲级研究，另一项是旨在解析城市生态系统对野生蜂觅食行为影响的瑞士项目。研究采用标准化诱集巢对野生蜂进行采样，共设置80个采样点（苏黎世32个，其余4座城市各12个），采样点依据局域和景观尺度的可利用栖息地双梯度进行选取。研究人员从蜂巢中获取幼虫花粉样本，并通过DNA宏条形码技术 (DNA metabarcoding) 完成物种鉴定。本数据集提供了欧洲5座城市各采样点中，所研究蜂类的不同蜂巢内植物类群的组成信息，分辨率可达物种或属级水平。针对普通黄脸蜂 (Hylaeus communis) 而言，本研究首次报道了其幼虫食物的组成信息。